Method and apparatus for producing a filter rod for smoking articles

Abstract

An apparatus for continuous production of a filter rod for smoking articles includes a belt conveyor system for advancing a rod of filter material. The belt conveyor system has separate conveyor belts, having respective upper conveying runs arranged one downstream of the other. Speeds of the conveyor belts are controlled according to a predetermined ratio, which controls an axial stretching or compacting effect of the material of the filter rod from the transition between conveyor belts, to influence the characteristics of the produced filter rod. Additional operations can be performed in the area between the upper runs of the conveyor belts, which modify the configuration and/or structure of the filter rod, including shaping, marking or embossing of the filter rod; or filter material may form a filter rod outer layer. The apparatus can produce a filter rod having a coaxial configuration.

1 . A method for continuous production of a filter rod for smoking articles, said method comprising providing a belt conveyor system for advancing a rod of filter material along a forming path, wherein said belt conveyor system comprises at least one endless belt having an upper conveying run for conveying the filter rod,
 wherein said belt conveyor system comprises at least two separate conveyor belts, having respective upper conveying runs arranged one downstream of the other along said forming path, and   wherein in the transition area between the upper runs of said at least two separate conveyor belts, an operation is carried out that modifies configuration and/or structure of the filter rod comprising shaping of the filter rod cross-section and/or embossing and/or marking of a surface of the filter rod and/or supplying filter material to form an outer layer of the filter rod and/or shaping a wrapping sheet of the filter rod.   
     
     
         2 . A method according to  claim 1 , wherein the material forming the filter rod is free of an outer wrapping sheet, 
     
     
         3 . A method according to  claim 1 , wherein speeds of movement of said conveyor belts are controlled according to a predetermined ratio, said predetermined ratio being selected to obtain a controlled axial stretching effect or a controlled axial compacting effect on the material of the filter rod as a result of transition from one conveyor belt to the other, to influence characteristics of the produced filter rod. 
     
     
         4 . A method according to  claim 1 , wherein a rigid wrapping sheet is associated with said filter rod, wherein shaping is imparted to said wrapping sheet. 
     
     
         5 . A method according to  claim 1 , for producing a filter rod having a structure with a coaxial configuration, comprising an outer layer of filter material, the outer layer of filter material being free of a wrapping sheet, and an inner body in the form of a tube of paper or cardboard, or an inner body of filter material, wherein in the transition area between the upper runs of said at least two conveyor belts, an outer layer of filter material is supplied, wherein the downstream conveyor belt is in contact with said outer layer of filter material, and the upstream conveyor belt feeds the inner body comprising said tube of paper or cardboard, or of said inner body of filter material. 
     
     
         6 . An apparatus for continuous production of a filter rod for smoking articles, comprising a belt conveyor system for advancing a rod of filter material along a forming path, wherein said belt conveyor system comprises at least one endless belt having an upper conveying run of the filter rod, wherein said belt conveyor system comprises:
 at least two separate conveyor belts, having respective upper conveying runs arranged one downstream of the other along said forming path, and   wherein between the upper runs of said at least two conveyor belts, a filter rod processing station is interposed for carrying out an operation changing a configuration and/or structure of the filter rod, comprising shaping of the filter rod and/or marking a surface of the filter rod and/or feeding of filter material to form an outer layer of the filter rod and/or shaping an outer wrapping sheet of the filter rod.   
     
     
         7 . An apparatus according to  claim 6 , further comprising:
 a motor associated with said conveyor belts, to control the movement of each conveyor belt, and   an electronic control unit for controlling said motor, and configured to implement a predetermined ratio between speeds of movement of said conveyor belts said predetermined ratio being selected to obtain a controlled axial stretching effect or a controlled axial compacting effect on the material of the filter rod as a result of transition from one conveyor belt to the other, so as to influence characteristics of the produced filter rod.   
     
     
         8 . An apparatus according to  claim 6 , wherein the material forming the filter rod is free of an outer wrapping sheet, 
     
     
         9 . An apparatus according to  claim 6 , for producing a filter rod having a structure with a coaxial configuration, comprising an outer layer of filter material, the outer layer of wrapping material being free of a wrapping sheet, and an inner body in the form of a tube of paper or cardboard, or an inner body of filter material, wherein between the upper runs of said at least two conveyor belts a processing station for feeding filter material is interposed, to form said outer layer of filter material, wherein the downstream conveyor belt is in contact with said outer layer of filter material, and the upstream conveyor belt is arranged to advance said inner body comprising said tube of paper or cardboard, or said inner body of filter material. 
     
     
         10 . A method according to  claim 1 , wherein a rigid wrapping sheet is associated with said filter rod, the wrapping sheet comprising a crimped sheet, wherein shaping is imparted to said wrapping sheet to form a circular cross-sectional tube shape in the transition area.